This invention pertains generally to an apparatus which includes identifying indicia readily readable without removing it from the object sought to be identified.
In my earlier U.S. Pat. No. 3,545,405 issued on Dec. 8, 1970, there is described an apparatus for investigating the migratory habits of macro-organisms and more specifically one wherein the identifying tag contains along the surface thereof coded information. This coded information is in the form of a predetermined pattern which is imparted on the surface of the body by a high energy heat source such as by focusing laser pulses in a predetermined pattern on the surface of the body. Although this particular identifying tag has been highly successful in its usage, certain instances exist where a more desirable form of identifying tag might be utilized.
The identifying tag described in my earlier issued patent has been used extensively in conjunction with investigating the migratory habits of Pacific Coast salmon. When such an identifying tag is applied to investigating the migratory habits of Atlantic Coast salmon certain drawbacks have been encountered. For instance, in the case of the identifying tag described in my earlier patent, it has been necessary to excise the implanted tag before decoding could be accomplished. In other words, removal of the tag from the salmon is necessary in order to properly decode the information contained thereon. In the case of Atlantic Coast salmon, where generally only a limited quantity are recovered, this requires destruction and loss of the specimen which is disadvantageous. Also, there are certain other instances wherein a tag which could be read, i.e., the information thereon decoded, while still within the body of the object is advantageous and desirable. By the means disclosed herein, such a system is provided which allows for all the advantages of my previously disclosed system and yet which does not necessitate removal of the identifying tag in order to obtain the coded information imparted thereon.